1. Field of the Invention
This invention concerns an improved method for pretreating soiled clothing articles in an automatic washer.
2. Description of the Art
In order to improve the cleanability of clothing articles in automatic washers, consumers routinely apply pretreating solutions such as detergents and clean enhancing agents to clothing articles before they are placed into automatic washers. These products and procedures generally require that a pretreating chemical separate and distinct from the detergent solution used in the automatic washer be applied to a clothing article and that the pretreating chemical is allowed to remain in contact with the clothing article for a period of time before the clothing article is placed in an automatic washer.
Manufacturers of automatic washers have attempted to assist consumers by incorporating pretreatment steps into preprogrammed automatic washer processes in order to eliminate the need for consumers to manually pretreat clothing articles. Stain treatment processes based on spin and spray treatment of fabrics during the wash cycle are known. There are a number of patents describing variations of this type of process. There are also a number of automatic washers on the market that are capable of performing clothing pretreatment steps. In general, the patents and automatic washers attempt to either reduce the amount of detergent solution used to saturate the textile wash load by increasing the detergent concentration or they attempt to solve suds lock issues which arises as a result of the use of low liquid volume/high detergent concentration solutions in automatic washer pretreatment processes.
U.S. Pat. Nos. 5,507,053 and 5,219,270 disclose automatic washers that disclose stain pretreatment apparatuses or methods. Suds lock issues caused by stain removal processes are disclosed for example in U.S. Pat. Nos. 6,591,439, 6,584,811, 6,393,872, 6,269,666, 4,784,666 and 4,987,627. The specifications of each of these eight patents are incorporated herein by reference.
Using small volumes of concentrated washing solutions improves wash load clean efficiency. However, since wash load size can vary, there is a risk that the concentrated washing solutions will be entirely absorbed onto the wash load used creating suds lock. There is also a risk that too much water will be used to dilute the concentrated washing solutions thereby reducing cleaning efficiencies. Despite the variety of automatic washer pretreatment methods and apparatuses currently available, there remains a need for improved washing processes and methods that are able to use small volumes of concentrated washing solutions.